How frequencies are stored in x_out array of 1D FFT?

[audrius]

Hello,
Could you please explain how frequencies are stored in x_out array of 1D FFT?
I pretty sure, that the real and imaginary parts of the zero frequency component are in x_out[0] and x_out[1];
Where are the real and imaginary parts of positive frequencies increasing in magnitude stored?
Where are the real and imaginary parts of negative frequencies increasing in magnitude stored?
And where is real and imaginary parts of the one aliased point that contains the most positive and the most negative frequency stored?

Thank you,
Audrius

[audrius]

Quoting - audrius

Hello,
Could you please explain how frequencies are stored in x_out array of 1D FFT?
I pretty sure, that the real and imaginary parts of the zero frequency component are in x_out[0] and x_out[1];
Where are the real and imaginary parts of positive frequencies increasing in magnitude stored?
Where are the real and imaginary parts of negative frequencies increasing in magnitude stored?
And where is real and imaginary parts of the one aliased point that contains the most positive and the most negative frequency stored?

Thank you,
Audrius

Hello everyone,
Actually I was expecting a fast response to my question.

Is my question clear or it is so difficult?

My question is:

What is arrangement of frequencies in x_out array: what is the index of zero frequency, and what are the indexes of positive and negative frequencies?

Thank you ,
Audrius

[Gennady_F_Intel]

Quoting - audrius

Hi,

In discrete transforms shifting frequency (it is discrete) by N is invariant, so the result

for frequency -|f| is the same as result for frequency N-|f|.

For negative frequency you should look at the end of data.

Say, -1 is N-1, -2 is N-2 etc, 0th frequency is the same as Nth frequency,

but Nth is not in the data (only 0...N-1 are)

--Gennady